Xpert艰难梭菌检测系统的临床应用评价

Clinical application evaluation of Xpert detection system of Clostridium difficile

目的评估Xpert艰难梭菌检测系统的临床应用价值。方法选取43份腹泻粪便标本,采用厌氧培养法、VIDAS检测A/B毒素法和Xpert艰难梭菌检测系统检测艰难梭菌,以产毒培养法作为金标准对检测方法进行评价,并比较不同检测方法对临床标本检测结果的一致性。通过自配027型标准菌株模拟粪便标本,验证Xpert艰难梭菌检测系统筛选027型流行株的能力。结果以产毒培养法为金标准,Xpert艰难梭菌检测系统的敏感性和特异性分别为90.9%和93.8%,阳性和阴性预测值分别为83.3%和96.8%。与产毒培养法结果一致性检验Kappa值为0.822(P<0.05),与VIDAS检测A/B毒素法结果一致性检验Kappa值为0.419(P<0.05);027型标准菌株模拟粪便标本检测结果阳性并报告为027型。结论 Xpert艰难梭菌检测系统能够快速准确地检测粪便标本中的艰难梭菌相关基因,且能准确报告027型高产毒力菌株。

Objective To evaluate the clinical application value of Xpert detection system of Clostridium difficile（ C. difficile）. Methods A total of 43 stool specimens from the patients with diarrhea were collected,and C. difficile in stool specimens were detected by the Xpert detection system,the toxigenic culture method,and the toxin detection method which detected the toxin of C. difficile by VIDAS automatic analyzer after anaerobic culture,respectively. The analytic performance of Xpert detection system was evaluted based on the toxigenic culture method as the gold standard. Meanwhile,the consistency of the results from different detection methods was compared. The ribotype 027 strain（ ATCC BAA-1870） simulating the stool specimen was further used to verify the Xpert detection system.Results Based on the gold standard of the toxigenic culture method,the sensitivity,specificity,positive predictive value and negative predictive value of the Xpert detection system were 90. 9%,93. 8%,83. 3% and 96. 8%,respectively. The Kappa values for the consistency between the Xpert detection system and the toxigenic culture method or the toxin detection method were 0. 822（ P〈0. 05） and0. 419（ P〈0. 05）,respectively. Moreover,the ribotype 027 strain simulating the stool specimen was verified by the Xpert detection system successfully. Conclusion The Xpert detection system may rapidly and accurately detect the C. difficile in stool specimens,especially the ribotype 027 strain with high toxicity.